Toxicokinetics of emodin are being studied in F344 rats and B6C3F1 mice. Bioanalytical method for quantitation of emodin and its glucuronide conjugate have been developed. Groups of rats and mice have been dosed with emodin intravenously at one dose or orally at three doses. Plasma concentrations of emodin and its glucuronide conjugate are being determined. Preliminary data indicate a relatively rapid elimination of emodin. Bioavailability of emodin will be estimated.